Summary: Saccade-Related Activity in the Parietal Reach Region
LAWRENCE H. SNYDER, AARON P. BATISTA, AND RICHARD A. ANDERSEN
Division of Biology, California Institute of Technology, Pasadena, California 91125
Snyder, Lawrence H., Aaron P. Batista, and Richard A.
Andersen. Saccade-related activity in the parietal reach region. J.
Neurophysiol. 83: 1099­1102, 2000. In previous experiments, we
showed that cells in the parietal reach region (PRR) in monkey
posterior parietal cortex code intended reaching movements in an
eye-centered frame of reference. These cells are more active when an
arm compared with an eye movement is being planned. Despite this
clear preference for arm movements, we now report that PRR neurons
also fire around the time of a saccade. Of 206 cells tested, 29% had
perisaccadic activity in a delayed-saccade task. Two findings indicate
that saccade-related activity does not reflect saccade planning or
execution. First, activity is often peri- or postsaccadic but seldom
presaccadic. Second, cells with saccade-related activity were no more
likely to show strong saccadic delay period activity than cells without
saccade-related activity. These findings indicate that PRR cells do not
take part in saccade planning. Instead, the saccade-related activity in
PRR may reflect cross-coupling between reach and saccade pathways